This invention relates to an engine starter and more particularly to a moisture drain structure for a vertical shaft engine starter.
The conventional engine starter for starting a vehicular internal combustion engine comprises a pinion engageable with an engine ring gear and a d.c. electric motor for driving the pinion. Such engine stater also comprises a front bracket on one end portion of the armature rotary shaft of the d.c. motor and a rear bracket on the other end portion of the armature rotary shaft. The front bracket is on the side of the armature rotary shaft on which the pinion is mounted. The engine starter is usually installed with its rotary shaft positioned horizontally.
Since the engine starter is mounted in an engine compartment when it is used in a vehicle, splashed water can easily enter into the starter through a clearance formed around the pinion when the vehicle crosses a shallow river or a water pool. The water or moisture thus entered into the interior of the engine starter must be drained.
FIG. 1 illustrates a rear bracket 1 used in a conventional engine starter of the horizontal shaft type provided with a moisture drain structure for draining the moisture entered into the engine starter as above discussed. It is seen from FIG. 1 that the rear bracket 1 has formed at its lower portion a moisture drain hole 2 into which a rubber tube 3 is inserted and attached by press-fit to extend downwardly. The rubber tube 3 attached to the drain hole 2 is for the purpose of preventing the water splashed by wheels or the like from the below from easily reaching the interior of the engine starter through the drain hole 2.
However, when the engine starter is to be installed with its armature rotary shaft of the d.c. electric motor oriented vertically, with the front bracket on the pinion side positioned at the upper portion and with the rear bracket at the lower portion, a question arises as to how the moisture drain structure should be arranged. This is because there is provided substantially no space below the rear bracket when the starter is vertically installed and therefore it is almost impossible to mount the rubber tube for preventing the ingress of splashed water from the below. Also, while a relatively large drain hole must be formed in the bottom wall of the rear bracket in order to attach the rubber tube, it is very difficult to find such a large wall area of the rear bracket bottom wall in which the large drain hole can be formed when the starter is vertically positioned.